Shock indicator



N. A. PALMGREN.

SHOCK INDICATOR.

APPLICATION FILED APR. 17. 1919 Patented Dec.12,1922.

2 $HEETSSHEE1 I.

- INVENTOR 72m d By Aim/ways, (Ska/N 9M1 Y m N. A. PALMGREN.

SHOCK INDICATOR.

APPLICMION FILED APR.17.1919.

Patented Dec. 12, 1922.

2 SHEETSSHEET 2.

INVENTOR 1? .-I/1ur1m's, @Nmuu Oak/x1 a 'h tow Patented Dec. 12, 1922.

UNITED STATES PATENT OFFICE.

NILS ABVID PALKGREN, OFGOTTENBOBG, SWEDEN, ASSIGNOB TO AKTIEBOLAGETSVENSKA KULLAGERFABRIKEN, OF GOTTENBORG, SWEDEN, A CORPORATION OFswannn.

Application filed April 17 To all whom. it may concern:

Be it known that I, NILs Anvn) PALMGREN, a subject of the King ofSweden, residing at Gottenborg, in the Kingdom of Sweden, have inventeda new and useful Improvement in'Shock Indicators, of which the followingis a specification. I

The present invention refers to a shock indicator which has for itspurpose to produce a space-time diagram by the aid of Y which it ispossible in a well-known manner to determine the acceleration at everymoment of the motion and thus also the magnitude of the force producingthe shock, provided that the mass put into motion is known.

The invention consists principally of a paper strip or the like movablewith a constant or variable velocity, and a pen-point (or equivalentmarker) cooperating with said'strip and arranged on a heavy body movablein a certain direction and relatively to the paper strip, the said bodybeing connected through the'intermediary of an easily yielding member,such as a weak spring, to the part of the indicator supporting the paperstrip or the like.

The accompanying drawings illustrate an embodiment of the indicator inwhich the paper strip is supposed to move with a variable speed.

Fig. 1 is a vertical section of the indicator. Fig. 2 is a plan view ofthe indicator with the protecting cap removed. Fig. 3 is a section onthe line AA in Fig. 2. Fi 4 is a horizontal section on the line B inFig. 1.

Referring to the drawings, 1, denotesthe indicator casing which isintended to be mounted on the object, such as for instance a journal boxfor a railway carriage, on which the shocks are to be observed. 11 thecasing 1 there is a tubular standard 2 serving as a guide for the heavybody 4 whlch supports the pen-point 3, and which is movable in itslongitudnal direction and is guided 1n the standard 2 by means ofrollers 5 journaled at both ends of the body, said body being supportedby a weak coil spring 6 bearin against an annular abutment 7 in the stanard 2. In the casing l'there is further an upright 8 supporting arotatable drum 9 over which the paper strip 10 moves, and by means ofwhich drum said paper strip is guided snoox mnrca'ron.

1919. Serial No. 290,778.

past the pen-point 3 which is supported by a spring 11 secured to thebody 4. The paper strip is wound off from a reel 12 and it is wound upona reel13 which latter is driven by means of a suitable source of power,such as for mstance a small electric motor 14, Figs. 3 and 4. The speedof the motorboing constant, the speed of the paper strip will becomeincreased as it is wound up on the reel 13, hence it is necessary bymeans of a special'device to register the time. In the embodiment of theshock indicator illustrated, the said device consists of anelectromagnet 15 the armature 16 of which is movable in the directiontowards the magnet against the actionof a spring 17, and supports at itsupper end,. a pen-point 18 cooperating with the paper strip 10. Byallowing an impulse of current to flow at definite intervals through theelectromagnet 15 which will then attract'its armature 16, there will beproduced by means of the pen-point 18 a diagram on the paper strip,which diagram marks the time-scale of the space diagram independently ofthe speed of the strip.

The shock indicator which is supposed to be mountedon an object, such asa journal box for a railway carriage, on which the shocks are to beobserved, acts in the following manner: v

If there are no shocks the pen-point 3 draws a line on the paper stripwhich line. owing to the long time of oscillation of the weak spring 6,may practically be considered rectilinear within a. limited length. Ifnow the object, i. e. the journal box, and thus also the indicator issubjected to a sudden shock, the said parts will be brought into motionrelatively to the object causing the shock. for instance a rail-joint.The body 1 will not take part in the said rapid movement. however, sinceowing to the inertia of said body and to its yielding support it ispractically independent of the other parts of the indicator. The paperstrip 10 will thus perform a movement relatively to the penpoint 3 onthe body 4 in a direction parallel to the direction of movement "of thebody 4 in the standard 2. so that the pen-point deviates from its normalpath, said deviation indicating the magnitude of the relative movementor space between the a-per strip each moment of the movement. By the aidof the time-scale drawn simultaneously by the pen-point 18 it ispossible in a wellknown manner to determine the acceleration of the massbrought into motion and thus theforce of the shock.

By driving the strip 10 with a definite constant speed which may beeffected with a suitable clockwork, the device for drawing thetime-diagram may be dispensed with.

I claim:

1.' Ina shock indicator, thecombination of a frame, means for guiding ahorizontally moving paper strip, a heavy body movable in said frame andguided to perform a rectilinear vertical movement, a spring supportingsaid body, said spring belng of barely sufiicient strength to uphold theweight of the body, a pen-point connected with said body adapted to marksaid paper strip, and a second pen-point and means for moving itperiodically to mark said strip for indicating time thereonindependently of the speedof the "strip.

2. In a shock indicator, the combination of a frame, means for guiding amoving paper strip, a heavy body mounted in said frame so that it mayperform a rectilinear movement vertically and relatively to said paperstrip, rollers guiding said body at its .ends m such manner as to giveit a frictionless movement, a spring supporting said body, said sprlngbeing long and su ple and of barely sufiiclent strength to upliold theweight of the body, and a pen-point connected to said body to mark saidpaper strip.

3. In a shock indicator, the combination of a frame, means for guiding amoving paper strip, a heavy body mounted in said frame so that it mayperform a rectilinear movement vertically and relatively to said paperstrip, guides for said body having parallel inner guiding faces, rollersjournaled frame on anti-friction vertical guiding *means adapted topermit it to move in vertical rectilinear direction with negligiblesprin having great length and flexibility and arely sufiicient stress touphold the weight of said body so that the body is given a floatingsuspension which yields to the slightest movement, and recording meansadapted to move a strip horizontally and mark thereon a sinuous lineindicating the relative vertical movements between the frame and body,whereby to record up and down movements of said frame.

NILS ARVID PALMGREN.

. friction, a spring supporting said body, said

